The number of gray wolves in the northern Rocky Mountain region declined about 7% last year, the first significant population drop in the region since wolves were reintroduced in 1995.
The decrease follows the removal of federal endangered species protections and the approval of wolf hunts in several Western states.
"There's no surprise" in the numbers, said Mike Jimenez, wolf management and science coordinator for the U.S. Fish and Wildlife Service. "The states are very carefully bringing the population down."
At the end of 2012, federal and state biologists counted 1,674 gray wolves in what is known as the northern Rocky Mountain distinct population segment, according to an annual report released Friday by the wildlife service. That was down from 1,804 the previous year, which represented the highest year-end count since wolves were reintroduced to Yellowstone National Park in the mid-1990s.
The northern Rockies population is found in Montana, Idaho, Wyoming, the eastern portions of Washington and Oregon, and north-central Utah. States assumed management of wolves within their boundaries when the population was delisted during the last two years and immediately authorized hunts.
In 2012, hunters and trappers killed a total of 570 wolves in Montana, Idaho and Wyoming. An additional 231 wolves were killed in the region because they were a threat to livestock.
Wildlife advocates have argued the delisting was premature and have criticized the hunts, which drew attention last year when the well-known alpha female of a Yellowstone pack was shot by hunters outside park boundaries.
The number of breeding pairs fell last year to 103 from 111 in 2011. But the number of confirmed gray wolf packs rose nearly 12% to 321.
"The wolf population may be stabilizing at some yet undetermined lower equilibrium," the report said. If wolf numbers fall below a certain level, the Fish and Wildlife Service will reevaluate the listing. But the report, based on information gathered from state and federal agencies, didn't raise any concerns.